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OEM Carrier Transformer 40VA 120V/24V for C50A703564
Carrier

OEM Carrier Transformer 40VA 120V/24V for C50A703564

SKU: CARRIE-C50A703564-TRANSFORMER-HT01BD702 Brand: Carrier

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Texas CMBL #19328542014
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OEM Carrier 40VA Control Transformer HT01BD702 for Model C50A703564

This is the OEM factory-specified replacement transformer for the Carrier C50A703564 commercial rooftop unit. The control transformer steps down 120V line voltage to the 24V AC signal used by your thermostat, contactor coils, and control board. When this component fails, the entire control circuit loses power — the result is a completely unresponsive system: no thermostat display, no contactor pull-in, and no staging response. It is one of the first components to inspect when a unit appears totally dead despite confirmed line voltage at the unit.

  • Specs: 40VA rating | 120V primary / 24V secondary | OEM part number HT01BD702 | Factory-matched output tolerance for reliable low-voltage circuit performance
  • OEM vs Generic: OEM transformers are wound to exact VA and voltage specifications for the C50A703564 control circuit load. Generic units often underrate VA capacity, causing thermal cutout trips under normal thermostat and accessory loads — leading to repeat failures and unnecessary callbacks.
  • Install difficulty: 2/5 — Disconnect all power before servicing. Tools needed: flathead and Phillips screwdrivers, multimeter, wire nuts or terminal connectors. Confirm 0V on primary terminals before touching wiring. Photograph existing wiring connections before removal.
  • Warranty: 1-year OEM factory warranty. In-stock units ship the same business day from our warehouse.

Compatibility: Designed as a direct OEM replacement for the Carrier C50A703564 commercial rooftop packaged unit using part number HT01BD702. Verify your existing transformer's VA rating and primary/secondary voltages on the unit data plate or wiring diagram before ordering. Our parts specialists are available to confirm fitment prior to purchase — order with confidence and get back up and running fast.

Shipping Information

  • Orders placed before 3PM CST ship same business day
  • Standard delivery: 2-5 business days
  • Express shipping available at checkout
  • Free shipping on orders over $75
  • Tracking number emailed upon shipment

Return Policy

  • 30-day returns on unused parts in original packaging
  • Electrical parts (capacitors, contactors, control boards) are final sale once installed
  • Email info@nationalhvacparts.com to initiate a return
  • Refunds processed within 5-7 business days

Frequently Asked Questions

Does this Transformer fit my Carrier C50A703564?
Yes. This is the factory-specified OEM transformer for the Carrier C50A703564. It is a direct drop-in replacement that fits without modification. Always verify the model number on your equipment nameplate before ordering.
How do I replace the transformer on my Carrier C50A703564?
Difficulty: Medium (30–45 min)
Step 1: Turn off breaker. Step 2: Photo wiring connections. Step 3: Disconnect wires from old transformer. Step 4: Remove mounting hardware. Step 5: Install new transformer, reconnect wires matching voltage ratings. Step 6: Verify 24V output with multimeter.
My thermostat has no power. What failed?
Thermostat with no display = failed 24V transformer (or blown control board fuse). Check the 3A/5A fuse on the control board first ($1–$5 fix). If fuse is good but no 24V output from transformer, replace transformer.
Is this transformer compatible with Bryant or Payne too?
Many Carrier parts are cross-compatible with Bryant and Payne since all three brands are manufactured by Carrier Global Corporation. The same physical part is often used across brand labels with different model numbers. To verify: check your Bryant or Payne equipment service manual for cross-compatible part numbers, or email info@nationalhvacparts.com with your model number.
Should I use OEM or aftermarket for my Carrier transformer?
OEM recommended for reliability and warranty compatibility. OEM parts match exact factory specifications for proper fit, performance, and safety. While aftermarket alternatives cost less upfront, the risk of improper fit and reduced lifespan usually makes OEM the better value long-term.
How fast does National HVAC Parts ship?
Orders placed before 3:00 PM CST ship the same business day. Standard delivery is 2–5 business days anywhere in the continental United States. Express shipping available at checkout. We ship from Houston, TX to all 50 states. 30-day return policy on all parts.
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Mike Rivera
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